WEG CFW-11 Series - Page 73

Installation and Connection
3
CFW-11 | 3-43
In reference to the type and details of installation, follow the recommendations of IEC 60034-25 "Guide for
Design and Performance of Cage Induction Motors Specifically Designed for Converter Supply" - refer to a
summary in Figure 3.33 on page 3-43. Refer to the standard for further details and eventual modifications
related to new revisions.
Keep motor cables away from other cables (signal cables, sensor cables, control cables, etc.), according to
Table 3.11 on page 3-43.
The grounding system shall be well interconnected among the several installation locations such as the
grounding points of the motor and the inverter. Voltage difference or impedance between the several points
may cause the circulation of leakage currents among the equipment connected to the ground, resulting in
electromagnetic interference problems.
Table 3.11 - Minimum separation distance between motor cables and all other cables
Cable Length Minimum Separation Distance
≤ 30 m (100 ft) ≥ 10 cm (3.94 in)
> 30 m (100 ft) ≥ 25 cm (9.84 in)
AFe
PEs
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
V
U
W
SCu
PE
PE
PE
U
VW
(a) Symmetrical shielded cables: three concentric conductors with or without a ground conductor, symmetrically
manufactured, with an external shield of copper or aluminum.
PE
SCu
W
U
V
(b) Alternatives for conductors up to 10 mm
2
Notes:
(1) SCu = copper or aluminum external shielding.
(2) AFe = steel or galvanized iron.
(3) PE = ground conductor.
(4) Cable shielding shall be grounded at both ends (inverter and motor). Use 360º connections for a low impedance to high-frequencies.
(5) For using the shield as a protective ground, it shall have at least 50 % of the power cables conductivity. Otherwise, add an external ground conductor
and use the shield as an EMC protection.
(6) Shielding conductivity at high-frequencies shall be at least 10 % of the power cables conductivity.
Figure 3.33 - (a) and (b) - Motor connection cables recommended by IEC 60034-25
Connection of the motor cable shield to ground:
Connection of the motor cable shield to ground: make a connection with low impedance for high frequencies.
Frame sizes B and C:
There is a kit for connection of the shielding of power cables that is supplied with the inverters (except for inverters
CFW11...T5O...NF...), which assembled on the bottom of the enclosure as shown in Figure 3.34 on page 3-44
and facilitates the connection of the shielding of motor and the line cable. That kit is also an acessory - PCSx-01.